Diabetes and obesity are very common in Western society. In spite of their prevalence, our understanding of their molecular basis is rudimentary. Mouse models of obesity and diabetes contribute greatly to a better understanding of how the environmental and genetic causes affect metabolism. Mouse Metabolic Core Laboratory supports Diabetes and Obesity programs by providing NIDDK investigators with standardized, high quality metabolic and physiologic phenotyping services for mouse models of diabetes, obesity and related disorders.. To characterize obesity we analyze body composition in live mice, body temperature, food intake, metabolic rates and diet induced thermogenesis. To study diabetes we perform insulin tolerance, glucose tolerance, 1st phase insulin secretion tests, glucagon, pyruvate and glutamate challenge tests, and conduct euglycemic-hyperinsulinemic clamp. To characterize pancreatic islets function we isolate islets from mouse and rat pancreas, induce type 1 diabetes using STZ and perform transplantation of islets from various sources into diabetic mice. We also measure the rates of triglyceride clearance and production, fatty acid oxidation in the whole animals and in isolated muscle, analyze tissue triglyceride content and perform hormone clearance tests and measure concentration of major metabolites and hormones in mouse serum.